Answer:
a. t = 1.43 s
b. d = 7.88 m
Explanation:
a. The time of flight can be found using the following equation:

Where:
 : is the final height = -10 m
: is the final height = -10 m 
 : is the initial height = 0
: is the initial height = 0
 : is the initial speed in the vertical direction = 0
: is the initial speed in the vertical direction = 0
g: is the acceleration due to gravity = 9.81 m/s²
By solving the above equation for "t" we have:

Hence, the ball will hit the ground in 1.43 s.
b. The distance in the horizontal direction can be found as follows:

Where:
x₀: is the initial position in the horizontal direction = 0
a: is the acceleration in the horizontal direction = 0 (it is moving at constant speed)

Therefore, the ball will travel 7.88 m before it hits the ground.
I hope it helps you!
 
        
             
        
        
        
1.8 is the mechanical advantage of the lever.
<h3>Definition of mechanical advantage</h3>
The theoretical mechanical advantage of a system is the ratio of the force that performs the useful work to the force applied, assuming there is no friction in the system. 
The advantage gained by the use of a mechanism in transmitting force specifically the ratio of the force that performs the useful work of a machine to the force that is applied to the machine.
Mechanical advantage is given by the ratio of the load lifted to the force applied to lift the load.
In this case, Mechanical advantage=L/E where L is the load and E is the effort applied.
Mechanical advantage= 90/50 =1.8
Question-you use a lever to lift a heavy tree branch. you apply a force of 50 n and the lever lifts the branch with a force of 90 n. what is the mechanical advantage of the lever?
To learn more about the Mechanical advantage visit the link
brainly.com/question/16617083
#SPJ4
 
        
             
        
        
        
The best and most correct answer among the choices provided by your question is the third choice or number 3.
<span>As an object falls freely toward the earth, the momentum of the object-earth system remains the same.</span>
I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!
        
             
        
        
        
Answer:
5.6*10^23. if 10^n is greater, that means its the larger value. hope dis helps 
Explanation: